Seam for woven wire fabric



May 13 1941- F. D. MARTIN SEAM FOR WOVEN WIRE FABRIC Filed June 19, 1940 mN mm Sm INV ENT OR.

BY f'emvc/s D. MART/Af ,4 rfa/emfrs Patented May 13, 1941 UNETED STATES PTENT QFFICE SEAM FOR WOVEN WIRE FABRIC Application June 19, 1940, Serial No. 341,291

5 Claims.

This invention relates to a seam for joining the ends of woven wire fabric to form an endless belt which is particularly useful in Fourdrinier paper machines. More particularly, the invention relates to a seam in woven wire fabric wherein each warp wire of the fabric embodies a cable formed by twisting together many strands of relatively ne wire. Cloth of this nature is more suited to withstand the heavy tension when in use on a paper machine than single stranded warp wires, and, additionally, is capable of wearing longer than single stranded wire.

Twisted cable, although possessing adequate strength and resistance to wear is not suited for joining by `brazing or welding and, hence, resort must be had to the use of a closing wire for joining the ends of the fabric together, but the use of a closing Wire, if placed around the end weft wires, is apt to pull them out of position.

An object of the present invention is to make a sewed seam which is well adapted for use in a Fourdrinier belt having warp wires in the form of twisted cables, and which will hold the ends of the fabric together firmly without distorting the weft wires to an objectionable degree.

The foregoing objects are accomplished by reinforcing each end of the fabric with two stitching wires, one of which is looped around the end weft wire and is anchored to successive weft wires in the body 0f the fabric, and the other of which is looped around the anchoring weft wires for the first stitching wire and is anchored further inwardly to the fabric. 'I'he loops formed in the outer stitching wire around the end weft wire provide suitable openings through which the closing wire may be passed. All of the bottom reaches of the wires used for stitching and closing may then be disposed substantially parallel to the direction of travel of the .belt on the paper machine. This arrangement serves to elevate the bottom of the seam above the wearing surfaces on the paper machine and thereby prolongs the life of the seam, and the life of the machine as well.

Referring now to the drawing, Fig. 1 represents, on an enlarged scale, a top plan view of a portion of a woven wire belt having a seam therein made in accordance with the present invention, and Fig. 2 is a section taken on the plane indicated by the line 2-2 in Fig. 1.

The body of the fabric has warp wires A, which are shown as twisted cables, and weft wires which are shown as single strands. The weft wires adjacent the seam opening are designated B, while those spaced inwardly from the seam opening are respectively designated BI, B2, B3, etc. Before the closing wire, designated C, is threaded into position, each end of the fabric is reinforced, preferably by two stitching wires, indicated at S and SI respectively. The outer stitching Wire S .extends back into the body of the fabric from the ends thereof, whereas the stitching wire SI lies wholly within the body of the fabric and serves to reinforce the weft wires around which the stitching wire S is anchored.

The stitching arrangement is the same on each side of the seam opening and, hence, the description will be confined to that appearing on one side. Commencing then with the stitching wire S, the loops may extend progressively around the fourth, fifth and sixth weft wires (counting the end weft wire as the first), from the seam opening and thence back around the fifth and fourth weft wires. Thus, the loops form a zigzag line across the body of the fabric around the weft wires B3, B4, and B5, with two warp wires between each loop. The reaches of the stitching wire S on the bottom of the fabric are laid parallel to the warp wires so as to minimize wear during use.

The stitching wire Sl is utilized for reinforcing the weft wires B3, B4, and B5 and extends further back into the body of the fabric around weft wires B1, B8, and B9. Thus, the stitching wire Sl tends to resist the pull exerted on the weft wires B3, B4, and B5, by the stitching wire S and operates to keep those weft wires substantially straight while the belt is in use. By utilizing a zigzag pattern for the inner loops on the wire SI, the load stresses are distributed over a plurality of weft Wires without distorting any part of the fabric.

After each end of the fabric is reinforced with stitching wires as described, the joint is completed by means of a closing wire C which passes around the end weft wires B and preferably through each opening between adjacent warp wires and through the outer loops of the wire S. The outer loops in the stitching wire S then function to retain the weft wire B in position, although to increase such retention, I prefer to solder the weft wires B to the warp wires before the stitching wires are applied to the fabric. The closing wire is so positioned that the bottom reaches thereof extend parallel to the warp wires so as to minimize the wear incident to the use of the belt on a' paper machine.

A seam made in accordance with the present method distributes the working stresses over a relatively wide area, thereby reducing distortion and results in a belt having greater strength and Wearing qualities. The seam thus constructed provides an effective joint for cable cloth or in cloth of such size that a welded or brazed seam is not suitable for use.

I claim:

1. A seam for an endless belt, the body of which is composed of Warp wires and weft wires, comprising a closing wire and two stitching wires, the stitching Wires being disposed on the same side of the seam opening, one stitching wire operating to reinforce the end weft wire and being anchored to spaced weft wires in the body of the fabric and the other stitching wire being located Wholly Within the body of the fabric and operating to reinforce the weft wires which serve to anchor the first stitching Wire.

2. A seam for a Woven wire belt having Warp Wires and weft Wires, comprising a closing wire and two stitching Wires, the stitching wires .being positioned. on the same sideof they seam opening, one stitching wire beinglooped around the end weltA wire and extendingv around a plurality of weft wires spaced inwardly from the seam opening,. and the other stitching .Wire being disposed wholly within the bodyof the. fabric and being looped aroundthesame weft wires that are engaged by the innerw loops of the first stitching wire, but on the sides opposite those engaged by the iirst stitching wire so as to resist the pull exertedthereby, the second stitching wire extending around a plurality of weft wires disposed farther from the sea-rn opening than those engaged by the rst stitching wire and the closing WireY extending across the seam opening and passing around the Vlast weft wire at each side of the seam opening.

3. A searn for a woven wire belt having warp wires and weft wires, and comprising a closing wire which extends across the seam opening and is looped around the end weit Wire on each side of the seam opening and in each space between adjacent warp Wires, .there being two stitching wires on each side of the seam opening, one of the stitching wires engaging the end weft Wire and being anchored in the body of the belt around spaced weit wires other than the end weft Wire, and the second stitching wire being disposed wholly Within the belt and extending around the weft Wires which serve to anchor the iirst stitching wire, and being anchored to the belt on spaced weft Wires other than those around which the iirst stitching Wire is passed.

4. A seam for woven wire ybelts having warp wires and weft wires, and comprising two stitching Wires on each side of the seam opening and a closing wire extending across the seam opening, each stitching wire having inner and outer loops, all o1" the outer loops of one stitching wire extending around the end weft wire, and the inner loops extending around three successive weft wires, and the outer loops of the inner stitching Wire extending around the same weft wires as those engaged by the inner loops of the outer stitching wire, and the inner loops of the inner stitching' wire extending around three weft wires other than those engaged by the iirst stitching wire, and a closing wire extending through loops formed by the outer stitching wire and passing around only the end weft Wires on` each side of the seam opening.

5.. A searnfor awoven Wire belt having warp wires'and weft wires, there being two stitching wires on eachy side of the seam4 opening, one of said. stitching wires being looped around the -end weft wire and extendingk .back into-the body of the fabric, and being loopedA around a series of weft wires in regular pattern across the belt, and the other stitching wire being looped around the same weft Wires that are engaged by the inner loops of the first weft wires, the inner loops of the second stitching wire extending around three weft Wires other than those engaged by the iirst stitching wire, and means for joining the ends of the fabric together.

FRANCIS D. MARTIN. 

